Thanks. Due to some bad dupont cable connection the program was not entering the void loop() and not printing to the console. Was not aware about a hardware serial print. It is stable now.

@qqlapraline Just use a 5V pro mini and get rid of level converter and mosfet!
Power the 5V HC-SR04 sonar with a pro mini digital pin.
Switch on the sonar for doing a measurement and then switch off again and put the promini to sleep till the next measurement.

Thanks guys, that makes it clear for me...

@mfalkvidd Thanks for confirming about the BC message being normal protocol.
I have used the log parser (great!) and the trouble shooting flowchart (great!).
I am currently powering thru USB but as the comms problem is intermittend I need some further investigation.

How can I implement the new 2.2.0 function

#define MY_SIGNAL_REPORT_ENABLED

Should it be defined in the node and/or the gateway?
Can it be used with NRF24?
How is the RSSI value reported?
Could not find a writeup on this new function.